diff --git a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
--- a/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
+++ b/llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp
@@ -758,14 +758,18 @@
 }
 
 /// Get the name of a profiling variable for a particular function.
-static std::string getVarName(InstrProfIncrementInst *Inc, StringRef Prefix) {
+static std::string getVarName(InstrProfIncrementInst *Inc, StringRef Prefix,
+                              bool &Renamed) {
   StringRef NamePrefix = getInstrProfNameVarPrefix();
   StringRef Name = Inc->getName()->getName().substr(NamePrefix.size());
   Function *F = Inc->getParent()->getParent();
   Module *M = F->getParent();
   if (!DoHashBasedCounterSplit || !isIRPGOFlagSet(M) ||
-      !canRenameComdatFunc(*F))
+      !canRenameComdatFunc(*F)) {
+    Renamed = false;
     return (Prefix + Name).str();
+  }
+  Renamed = true;
   uint64_t FuncHash = Inc->getHash()->getZExtValue();
   SmallVector<char, 24> HashPostfix;
   if (Name.endswith((Twine(".") + Twine(FuncHash)).toStringRef(HashPostfix)))
@@ -878,8 +882,11 @@
   // discarded.
   bool DataReferencedByCode = profDataReferencedByCode(*M);
   bool NeedComdat = needsComdatForCounter(*Fn, *M);
-  std::string CntsVarName = getVarName(Inc, getInstrProfCountersVarPrefix());
-  std::string DataVarName = getVarName(Inc, getInstrProfDataVarPrefix());
+  bool Renamed;
+  std::string CntsVarName =
+      getVarName(Inc, getInstrProfCountersVarPrefix(), Renamed);
+  std::string DataVarName =
+      getVarName(Inc, getInstrProfDataVarPrefix(), Renamed);
   auto MaybeSetComdat = [&](GlobalVariable *GV) {
     bool UseComdat = (NeedComdat || TT.isOSBinFormatELF());
     if (UseComdat) {
@@ -920,7 +927,7 @@
     ArrayType *ValuesTy = ArrayType::get(Type::getInt64Ty(Ctx), NS);
     auto *ValuesVar = new GlobalVariable(
         *M, ValuesTy, false, Linkage, Constant::getNullValue(ValuesTy),
-        getVarName(Inc, getInstrProfValuesVarPrefix()));
+        getVarName(Inc, getInstrProfValuesVarPrefix(), Renamed));
     ValuesVar->setVisibility(Visibility);
     ValuesVar->setSection(
         getInstrProfSectionName(IPSK_vals, TT.getObjectFormat()));
@@ -955,8 +962,14 @@
   //
   // On COFF, a comdat leader cannot be local so we require DataReferencedByCode
   // to be false.
-  if (NS == 0 && (TT.isOSBinFormatELF() ||
-                  (!DataReferencedByCode && TT.isOSBinFormatCOFF()))) {
+  //
+  // If Fn in a comdat is not renamed, when NS==0, it is still possible for a
+  // different copy to need value profiling and cause the data variable to be
+  // referenced by code. Making the data private can cause relocation to
+  // discarded section linker errors.
+  if (NS == 0 && !(Fn->GlobalValue::hasComdat() && !Renamed) &&
+      (TT.isOSBinFormatELF() ||
+       (!DataReferencedByCode && TT.isOSBinFormatCOFF()))) {
     Linkage = GlobalValue::PrivateLinkage;
     Visibility = GlobalValue::DefaultVisibility;
   }
diff --git a/llvm/test/Transforms/PGOProfile/comdat.ll b/llvm/test/Transforms/PGOProfile/comdat.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/PGOProfile/comdat.ll
@@ -0,0 +1,35 @@
+; There are two main cases where comdats are necessary:
+; 1. standard inline functions (weak_odr / linkonce_odr)
+; 2. available externally functions (C99 inline / extern template / dllimport)
+; Check that we do the right thing for the two object formats with comdats, ELF
+; and COFF.
+;
+; Test comdat functions. Non-comdat functions are tested in linkage.ll.
+; RUN: opt < %s -mtriple=x86_64-linux -passes=pgo-instr-gen,instrprof -S | FileCheck %s --check-prefixes=ELF
+; RUN: opt < %s -mtriple=x86_64-windows -passes=pgo-instr-gen,instrprof -S | FileCheck %s --check-prefixes=COFF
+
+;--- main.ll
+declare void @llvm.instrprof.increment(i8*, i64, i32, i32)
+
+$unnamed = comdat any
+$weakodr = comdat any
+
+; ELF:   @__profc_unnamed.[[#]] = linkonce_odr hidden global {{.*}} comdat, align 8
+; ELF:   @__profd_unnamed.[[#]] = private global {{.*}} comdat($__profc_unnamed.[[#]]), align 8
+; COFF:  @__profc_unnamed.[[#]] = linkonce_odr hidden global {{.*}} comdat, align 8
+; COFF:  @__profd_unnamed.[[#]] = linkonce_odr hidden global {{.*}} comdat, align 8
+define linkonce_odr void @unnamed() unnamed_addr comdat {
+  ret void
+}
+
+;; weakodr in a comdat is not renamed. We may have other copies which are non-local
+;; (if value profiling is enabled). If we cannot make this profd private, the non-prevailing,
+;; when inlined into another function, may reference a discarded profd.
+
+; ELF:   @__profc_weakodr = weak_odr hidden global {{.*}} comdat, align 8
+; ELF:   @__profd_weakodr = weak_odr hidden global {{.*}} comdat($__profc_weakodr), align 8
+; COFF:  @__profc_weakodr = weak_odr hidden global {{.*}} comdat, align 8
+; COFF:  @__profd_weakodr = weak_odr hidden global {{.*}} comdat, align 8
+define weak_odr void @weakodr() comdat {
+  ret void
+}